Perhaps you have seen the captain's patches certain NFL players are wearing on the upper right chest of their jerseys this season. The patches . . .

"What the heck is a captain's patch?" the Baltimore Ravens' Jonathan Ogden asked.

Oh. It's a square patch with the letter "C" and four stars across the bottom. A player receives a gold star for each year he is a team captain and . . . "I don't even know what the captain's patch is about," the Ravens' Ray Lewis said.

Well, the purpose, according to the NFL, is to "support and recognize the importance of team leadership through the role of captains."

NFL teams always have appointed captains, but they didn't distinguish those players with symbols, like other sports did -- think of the "C" on a hockey sweater or the armband of a soccer player. Prior to this fall, only three teams in league history -- the 1983 Cowboys, the 1992 Chargers and the 1994 Patriots -- designated captains with either patches, lettering or insignia, according to Paul Lukas, who maintains the Uni Watch blog.

That changed this season, at the recommendation of the league's six-member player advisory council (which includes Washington Redskins wide receiver James Thrash). Teams that designate season-long captains can have up to six players wear the "C" patch on their uniforms. The patches are not mandatory.

"We felt that re-establishing the role of captains, where you could see that leadership come through in the locker room on a season-long basis, was critical," NFL Commissioner Roger Goodell told ESPN's Chris Mortensen in an interview in early September. "So we're celebrating, we're acknowledging and we're promoting the values that come with being captains and that leadership responsibility that comes with it."

Teams were allowed to determine how they wanted to select their captains. Six teams -- the Ravens, Redskins, Packers, Jaguars, Vikings and Eagles -- opted for weekly captains, which means some of the league's biggest stars and archetypal leaders -- Lewis, Steve McNair, Brett Favre and Donovan McNabb -- aren't wearing the patches.

Some teams, like the Buffalo Bills, chose six captains and evenly divided them among the offense, defense and special teams. The Indianapolis Colts, on the other hand, voted for quarterback Peyton Manning as the offensive captain and linebacker Gary Brackett as defensive captain; a special teams captain is to be selected every week.

"The team captain from my standpoint is important," Indianapolis Coach Tony Dungy told the Colts' Web site. "We actually changed a couple of things we've done because of what the captains have told me. I think it's important for the guys to understand that these are our leaders."

As for the Ravens, they prefer to appoint their captains on a weekly basis because, as veteran place kicker Matt Stover puts it, "Our style is more of a plurality." Each week, Coach Brian Billick consults a group of veteran players to determine who will be the captains for the upcoming game. They generally select players who need to stand out in that particular game, though sometimes they'll pick a player who is returning home or is facing his former team.

In the season opener in Cincinnati, Stover, Lewis, McNair and special teams ace Gary Stills -- who have 52 years of NFL experience and 14 Pro Bowl appearances among them -- were the captains. Last week against the Browns, it was wide receiver Derrick Mason, cornerback Corey Ivy and long snapper Matt Katula (combined 21 years and two Pro Bowls).

"This is a team that has a lot of leadership, and to isolate two or three guys and say, 'Okay, you're it for the year,' that's not the way we work," Billick said. "We get leadership from a lot of guys, and we like to recognize that."

Besides, the most high-profile responsibility of a captain on game day is to walk to midfield for the pregame coin toss. "You've got to have somebody who has good luck to call the coin toss. That's about it," tight end Todd Heap said.

"Honestly, I don't remember the last time it mattered who the captain was on the football field," said Ogden, a 10-time Pro Bowl selection. "You know the guys are going to look to Ray or [safety] Ed Reed or Steve or [veteran center] Mike Flynn. Who cares if it's denoted on your uniform?"